Pathology Of Hypertension

1.

Pathology Of Hypertension

2. Hypertension - Introduction

Silent Killer – painless – complications
Leading risk factor – MI & Stroke
Number one reason for drug prescription
25% of population, <35% aware
Complications alert to diagnosis but
late…

3.

Classifications of Hypertension
Mild (1)
Systolic
140-159
Diastolic
90-99
Moderate (2)
160-179
100-109
Severe (3)
180-209
110-119
Very Severe (4) >210
>120

4.

Classifications of Hypertension
1. Benign Hypertension
2. Malignant / Accelerated Hypertension
(Diastolic >120)

5. Regulation of BP

BP = Cardiac Output x Peripheral Resistance
• Endocrine Factors
– Renin, Angiotensin, ADH, Aldosterone
• Neural Factors
– Sympathetic & Parasympathetic
• Blood Volume
– Sodium, Mineralocorticoids
• Cardiac Factors
– Heart rate & Contractility

6.

GFR
Renin by JGA
Aldosterone
Angiotensin II
Sodium Retention
Blood Volume
Vasoconstriction
P. Resistance
Hypertension

7. Hypertension-Risk factors

• Genetics- family history
• Diet-high intake of sodium
• Lifestyle-stressful
• Weight- obesity
• Alcohol-increased intake
• Oral contraceptives

8. Etiologic Classification:

I.
Primary/Essential Hypertension (95%)
II.
Secondary Hypertension (5-10%)
Renal
Glomerulonephritis
Renal artery stenosis
Adult polycystic disease
Endocrine
Cushing S., Thyrotoxicosis
Myxdema,
Pheochromocytoma
Acromegaly
Vascular
Coarctation of Aorta
Neurogenic
Psychogenic
Intracranial pressure

9. Renal Causes of HT

Polycystic Disease
Glomerulonephritis
Chronic pyelonephritis
Renal artery stenosis
Renal vasculitis – SLE
Renin producing tumors.

10. Renal Artery stenosis - Atrophy

11. Etiology

I- Secondary HT:
(Known abnormal control)
II- Essential HT
(Multifactorial etiology)
– Increased peripheral resistance
(sympathetic tone)
– Stress , hormonal, neural
– Genetic, familial, life style

12. Postulated mechanisms of Essential Hypertension

1.Defect in sodium excretion
2.Defect in cell membrane function:
-Na/Ca transport
-Increased vasoconstrictive response
3.Increased sympathetic response

13. Malignant Hypertension

• Rapidly progressive often leads to end
organ damage.
• May complicate any type of HTN
– Widespread arterial necrosis and thrombosis
– Rapid development of renal failure
– Hypertensive encephalopathy
– Left ventricular failure

14. Morphology:

• Large Blood Vessels (Macroangiopathy)
– Atherosclerosis. HT is a major risk factor in AS.
• Small Blood Vessels (Microangiopathy)
– Arteriolosclerosis
Organ damage:
• Heart
– LVH, Hypertensive cardiomyopathy
• Kidney
– Benign nephrosclerosis
• Eyes
– Hypertensive retinopathy
• Brain
– Haemorrhage, infarction

15. Vascular Pathology in Hypertension

Accelerates atherosclerosis
Potentiates aortic dissection
Cerebrovascular hemorrhage
Small vessel changes:
Hyaline
arteriolosclerosis
Benign hypertension
Hyperplastic
arteriolosclerosis
Malignant hypertension
Fibrinoid
necrosis
Malignant hypertension

16. Left Ventricular Hypertrophy

17. Subarachnoid Haemorrhage

18. Cerebral Hemorrhage

19. Lacunar Infarct

20. Benign Nephrosclerosis

21. Cerebral Infarction

22. Normal Retina - Fundoscopy

23. Hypertensive Retinopathy:

Grade I
Thickening of arterioles
Grade II
Arteriolar spasms
Grade III
Hemorrhages
Grade IV Papilloedema

24. Factors Indicating Adverse Prognosis in Hypertension

Black race
Younger age
Male sex
Persistent diastolic
pressure > 115 mm Hg
Smoking
Diabetes mellitus
Hypercholesterolemia
Obesity
Excess alcohol intake
Organ damage:
cardiac
eyes
renal
CNS